One well known basic type of bath and basin waste has an externally threaded tube defining a flow passage therethrough from its upper end to its lower end and which is adapted to fit into the drain opening provided in a bathtub or basin. A flange extends outwardly from the tube at its upper end and is arranged to engage the upper face of the bath or basin bottom about the drain opening. Typically, a flat rubber washer is fitted about the tube between the flange and the basin and a nut is screwed onto the tube so as to engage the lower face of the basin bottom and tighten the flange against the washer so that it forms a watertight seal therebetween. A trap or pipe is then connected to the lower end of the tube and in turn connected to a waste water drainage pipe which eventually is connected to the sewerage system. A grate is usually fitted in the tube adjacent the flange and is often cast therewith to prevent passage of cakes of soap, cloth and the like. Sometimes the grate is formed separately and is secured in the tube by a screw which is screwed into the centre of intersecting a diametral cross bars which are cast in the tube (commonly known as a “spider”). The upper end portion adjacent the flange is usually tapered inwards away from the upper end to accommodate a removable tapered plug therein for closing the flow passage.
A more recent type of basin outlet commonly referred to as a “pop-up” waste or outlet has become popular because it does not require a separate plug. Such basin outlets typically have a tube and flange similar to the basic bath and basin outlet described above but instead of a removable plug being used to close the flow passage, a cap is mounted in the flow passage adjacent the flange for up and down movement between an open position and a closed position so as to close the passage when it is down and open the passage when it is up.
In such known pop-up type outlets the cap seals against the flange or the inner face of the tubular portion immediately adjacent the upper end when down to close the passage and is spaced above the flange when up thereby opening the passage at its upper end. Movement of the cap is controlled by an actuation device to which the cap is connected such that closing of the passage is achieved by pushing the cap down against a spring loaded catch and released by pushing the cap further down to release the catch so that it rises to the open position under the force of a spring. In such pop-up type basin wastes, the upper face of the cap is normally flush with the flange (and the upper face of the basin bottom) when the cap is down in the closed position but protrudes significantly above the flange (and the basin bottom) when in the open position.
It will be appreciated that a large number of persons who use a wash basin to quickly wash their faces and hands or clean their teeth prefer to do so with running water direct from the basin faucet while the basin outlet is open and water can flow directly out of the basin. Unfortunately, the protruding cap of the presently available basin wastes can be a nuisance in such cases. Furthermore, the basin waste is typically more aesthetically pleasing when in the closed position than the open position but is rarely in the closed position and many people prefer to leave the basin waste open when not in use so that any drips drain away rather than overflow the basin.
A new type of bath or basin waste is described and illustrated in U.S. application Ser. No. 13/283837 to the present applicant which has some of the advantages of the pop-up type waste but which does not significantly protrude into the basin when in the open position. Bath and basin wastes according to that application are illustrated in FIGS. 1 to 8 of this application (“the earlier version”). One difficulty with the earlier version is that because the cap is flush with the flange when in the open position and below the flange when in the closed position, it is difficult to service the actuating mechanism and replace seals.